English

Shows the ventilation of electrowinning cell houses and electrorefineries as being a complex problem. Develops a systematic approach to define the important contaminant generation rates including heat, moisture and acid mist. Discusses fluid dynamic scale modelling as a powerful tool for solving a building's flow field and contaminant concentration field. Examines other associated problems, including wintertime fogging in the building and the high costs of make-up building heat. Presents the possibilities for reclaim of low-grade waste heat, and evaluates the economic impact.

Notes that many air conditioning and industrial installations function inefficiently since too little attention is paid to air movement in a room. Compares effect of inlet and exhaust air devices. Considers reduced ventilation need if pollution can be eliminated or reduced. States that ventilation efficiency is an indication of how efficiently the air is used in the occupation zone and that the air supply to a zone determines ventilation efficiency. Illustrates various forms of ventilation.

Indicates that 35-70% of a building's annual energy consumption is used by ventilation plant. Notes difficulty in determining which energy saving measures are most profitable but states that restricting fresh air supply tothat required is one measure that has not been considered and that most systems are designed for maximum capacity without facilities for varying load according to conditions. Describes plant which uses CO2-controlled ventilation in a sports hall. Illustrates circadian changes.

Discusses principle that the position of supply air devices has a considerable influence on the ventilation efficiency that can be achieved. Considers factors affecting ventilation efficiency and different ventilation models. Illustrates different air supply systems.

Describes method which permits long term tracer gas measurements in several separate rooms simultaneously. The method employs a fully automated constant concentration system developed at the laboratory for building physics at the Swedish Institute for Materials Testing. Describes measurement principles andpractice.

Over 200 reports of health hazard evaluations are available of sealed, air-conditioned buildings, requested by occupants who believe their buildings to be hazardous to their health. Describes a computer based building information system developed to extract relevant information about internal environmental measures, disease characteristics and history of occupants, as well as relevant features of the architecture and ventilation conditions of buildings.

Data collected in a LBL study on ventilation in four public buildings includes sensory evaluations of indoor environment and of physical and chemical properties of indoor air. Analyzes database to establish how the indoor odour acceptability criterion (acceptability by 80% of individuals entering theoccupied space) depends on other qualities of the indoor air. Finds that the staleness freshness rating correlates to the odour acceptability better than odour intensity alone. At low concentrations formaldehyde or aldehydes increase odour intensity but also improve odour acceptability.

Compares measured hourly data on indoor humidity with data obtained by calculative values for NBS Houston test houses and for the high mass test building in an environmental chamber. Measured values are usually very different from the calculated values if no considerations are given to moisture absorption and desorption phenomena that take place at the interior surfaces. Introduces the Tsuchiya model that permits the evaluation of room surface moisture absorption capability.

Looks at ventilation requirements for both odour and physical acceptability and pays particular attention to the differences between smoking and non smoking occupancy in an environmental chamber. Results imply that under non smoking conditions and with moderate humidity, between 5 and 10 cfm of fresh air per occupant should satisfy 75% of visitors, but that under smoking conditions, many times as much fresh air is needed for both odour acceptability and compliance with customary criteria values for smoke.

Describes a series of experiments to determine the ventilation performance of 2 different models of wall or window mounted heat exchangers. Determines their nominal efficiency by the measurement of tracer gas decay rates at several indoor locations. Notes significantly higher local ventilation efficiencies in rooms where heat exchangers are operating. Some preliminary tests indicate that internal leakage between the air streams contribute significantly to the ventilation inefficiency of these systems.